Guiding device for spiral pipe cleaners including steel wire coils coiled up with interspaces and rotatable around their axes by means of a drive machine separate from the guiding device. A guiding housing with an inlet opening at one end and an outlet opening for the coil at the other end has several jaws disposed in the guiding housing and positively engaging in the interspaces of the individual turns of the coil. These jaws are distributed on the circumference of the coil axis (A--A) and axially offset corresponding to the inclination of the helix.
Among experts, such cleaning devices are referred to as "spiral cleaners", although, strictly speaking, they are coils which are formed by coiling up a steel wire along a helical line.
Devices to guide coils are known from U.S. Pat. No. 4,447,926. These are tubes, drums or adaptor magazines which serve to hold coils but do not apply any feeding power to these coils.
Operating such devices is very difficult if such a driven spiral pipe cleaner or coil is to be used for a correspondingly long downpipe. The vertical length of such downpipes can indeed exceed 15 to 20 stories which requires a total length of the spiral pipe cleaner of approximately 60 m. During the cleaning process the spiral cleaner is assembled by joining parts together by means of couplings, and during removal of the coil these parts are disassembled again. The parts have a lengths between 4 and 5 meters and, depending on the coil diameter, a weight between 2 and 8 kg. For a total length of 60 m this results in a total weight between approximately 30 and 120 kg. The operator can handle such a weight only with great physical effort or even not at all. This increasingly creates problems when using these pipe cleaning machines with downpipes of great vertical length. It should also be considered that the cleaning coils are wet and/or dirty when they are retracted from the pipe after use which also accounts for difficult handling.
It is known to combine pipe cleaning machines having a driven holding drum during manufacture with an additional feeding device which positively engages in the coil for greater lengths.
According to U.S. Pat. No. 3,246,354, such a drum machine includes a feeding device which is equipped with a special belt drive; the speed of this belt drive is matched to the speed of the drum (differential effect). Such a machine involves a great deal of labor and costs and is difficult to transport.
In an another drum machine according to the U.S. Pat. No. 3,882,565 the advance feed is generated by a jaw chuck and controlled by a manually operated brake which demands total attention of the operator.
Due to large stored coil length, these drum machines do not involve the problem of assembling a long coil of relatively short parts by using couplings. However, what must be accepted is the heavy weight combined with unwieldy shape which must not be underestimated during transport and use as well as the risk of coil breaking; this occurs if the coil gets stuck during use and the drum continues rotating for several more revolutions due to its high moment of inertia.
The advance coupling of the drum machine in accordance with the British Patent No. 1,409,301 does not facilitate the operator's task during retraction of the coil since it is a mere manual device which requires manually compensating the retracting force in any case.
From the U.S. Pat. No. 3,329,044 a guiding device of the aforesaid kind is known, a "passive" device which uses the rotation of the coil generated by a separate drive machine, which is necessary in any case in order to produce a advance feed effect in the one direction and a retraction effect in the other direction, i.e. reverse direction of rotation. However, this device cannot be used with such a pipe cleaning machine where the coil in its entire length is assembled by combining parts by means of couplings. These couplings cannot pass through the guiding device during advance or retraction. Opening the housing so as to pass through the coupling would result in the loss of positive engaging and the coil axially slides through. The axial offset of the engaging elements corresponds only in a fraction to coil inclination since the engaging elements must be disposed on a helical line so as to avoid jamming. Hence, the axial offset of the three engaging elements corresponds just to one third of the coil inclination; this means it amounts only to a few millimeters. Hence, the engaging elements absolutely block the passing of a coupling.